The suspect was identified as 24-year-old Deshaun James Swanger. He was arrested at a transitional home, located at Southeast 80th Avenue and Sunnyside Drive, just a few blocks away from the restaurant.

Swanger has a criminal history, including charges of robbery, burglary and assault.

Deputies told KGW's Mike Benner that on Wednesday evening, Swanger walked into the restaurant, located at 12101 Southeast 82nd Avenue, at about 9 p.m., sat down, threw gasoline on the customer, then lit the victim on fire with a book of matches.

The victim's family identified him as 69-year-old Scott Ranstrom. He is in critical condition at Legacy Emanuel hospital.

“His face was like this big and he’s a skinny guy. And all red, and horrible-looking, burnt to a crisp. He was burnt to a crisp," Ranstrom's sister said. "They did that to my big brother. I don’t think I’ll ever get over it. It’s not fair.”

His family has set up a GoFundMe page to pay for his medical expenses.

Scott Ranstrom
(Photo: GoFundMe)

Deputies said Swanger and Ranstrom did not know each other.

Detectives are looking into the possibility that this case is related to another incident earlier this week, in which a person threw gasoline on a stranger at the Clackamas Town Center movie theater.

Deputies told KGW Thursday that they did not make the incident public based on an interview with the victim, who seemed to treat the incident as a joke. They will now interview the person again.

Denny's issued the following statement Thursday morning:

“We are deeply disturbed by the senseless, random act of violence that took place at our franchised-owned Happy Valley restaurant, and our thoughts and prayers are with our guest that was seriously injured. Both guests and team members acted quickly to help this guest and ensure the safety of others in the restaurant. We are actively assisting authorities in their investigation and we ask that anyone with information to please contact the Clackamas County Sheriff's office at 503-723-4949."

The Clackamas County homicide and violent crime teams are investigating.

Anyone with information about this case is asked to call the Sheriff's Office Tip Line at 503-723-4949 or by filling out the online form. Click here to fill out the form and reference CCSO Case No. 17-10537.